In industrial processes, various types of devices are applied, which measure, monitor, or, in given cases, control, physical or chemical, process variables, including variables such as e.g. temperature and pH-value. Such devices are subject to mechanical oscillations and vibrations from different process-related sources. This can lead to wear of a device, such that it no longer operates faultlessly. Even the complete failure of a device is possible. In order to be able to detect damage to a device or to predict when it might fail, a technique is to position a vibration sensor on a device participating in the process. A process device in combination with a vibration sensor is described in published International Application WO 2005/033639 A2.
The process device can be, for example, a sensor for monitoring a process variable. The vibration sensor is integrated into the sensor. A disadvantage of positioning directly on the device is that, in the case of malfunction or diagnosed imminent failure of the device, the device together with the vibration sensor must be replaced. The vibration sensor can, indeed, also be placed as an element on a superordinated control unit; however, then such must be located in direct contact with the process, which is, most often, not the case.